Guide for winding thread on transverse spools

ABSTRACT

A thread guide is slidably disposed in a guide way and in contact with a rotating thread roll having a continuous spiral guide groove. The thread guide has a runner contacting and moving with respect to the guide slot of the roller and an elongated extension arm ending in an upright thread guding device, the extension arm being aligned with the runner of the guide. The length of the extension arm determines the longitudinal acceleration of the thread being wound in the end areas of the spool as the runner passes through the end turnaround portion of the guide slot. The thread is accelerated away from the end of the spool, thus decreasing the possibility of thread buildup or hangover in this region. A double runner device is also provided and includes a positionally adjustable extension arm for the winding of conical spools.

United States Patent Tschentscher GUIDE FOR WINDING THREAD ON TRANSVERSE SPOOLS Primary ExaminerStanley N. Gilreath Attorney, Agent, or Firm-Markva & Smith [761 Inventor: NEQI EESQFEE zPh9f Cologne 91, Germany [22] Filed: Feb. 28, 1972 [57] ABS [21] Appl. No.: 229,848

A thread guide is slidably disposed in a guide way and [30] Foreign Application priority Data in contact with a rotating thread roll having a continu- S t 25 971 G 2148019 ous spiral gulde groove. The thread guide has a runner ep many contacting and moving with respect to the guide slot of the roller and an elongated extension arm ending in [52] Cl 242/43 an upright thread guding device, the extension arm [51] Int Cl i365}! 54/2'8 being aligned with the runner of the guide. The length of the extension arm determines the longitudinal [58] Fleld of Search 242/43 1583 158's celeration of the thread being wound in the end areas of the spool as the runner passes through the end turn- [56] References C'ted around portion of the guide slot. The thread is accel- UNITED STATES PATENTS erated away from the end of the spool, thus decreasing 2,830,456 4/1958 Stafford 242/l58.5 the possibility of thread buildup or hangover in this 2,934,284 4/1960 steegef 158-3 region. A double runner device is also provided and 3,059,874 10/ 1962 y 242/158-5 includes a positionally adjustable extension arm for 3,664,596 5/1972 Lenk 242/43 the Winding of conical Spools FOREIGN PATENTS OR APPLICATlONS 14,988 6/1968 Japan 242/43 6 Claims, 21 Drawing Figures K' 39 m XIY 25 PATENTEUSEP 11 m 3.836; 087

SHEET 3 BF 5 mimosa? 1 1 1 14 3.836138 7 mm an; s

r .lllli' I [114 GUIDE FOR WINDING THREAD ON TRANSVERSE SPOOLS BACKGROUND OF THE INVENTION This invention relates to a process and device for the winding of threads onto transverse spools. More specifically, it is directed to a thread guide device which is moved in an oscillating translatory movement parallel to the spools axis and imparting accelerated movement to the thread in the area of the spool ends to prevent buildup.

The occurrence of hard built-up edges during the winding of a transverse thread spool or bobbin is a constant problem. In the usual thread winding operations, the thread guide which lays the thread on the spool during the winding process remains longer in the vicinity of the end portions of the spool. It is desirable to move the thread at a constant predetermined translatory speed across the spool but this is impossible in the end turnaround areas. As the thread guide approaches the end of the spool, it decelerates to zero at the exact instant of turnaround and subsequently accelerates to the predetermined speed, moving in the opposite direction. The relatively long delay in the vicinity of the turnaround point causes additional thread material to build up in these areas of the spool.

These built-up areas in the vicinity of the end portions prevent the surface of the wound thread from being parallel to the cylindrical or conical spools. Generally, the areas near the ends taper inwardly towards the middle of the spool length, thus preventing geometrical cylindrical or conical spool shapes.

The built-up end areas of the spool produce what is called hardenings in the spool wound structure. This condition produces an impairment in the thread structure resulting in variations in thread tension. In addition, as the thread in drawn off from the spool, usually in an overhead or longitudinal direction, the thread filament must be pulled over the built-up area, causing tugs and temporary increases in the thread tension. It is also possible that whole thread layers may be pulled off at one time, causing breakage of the thread.

Handling of the threaded spool by the operator is also more critical during the packing, transport or mounting of the spools on the machines, since even slight finger pressure can cause the built-up edge to collapse and slip from the end of the wound portion. This condition is extremely undesirable because of the large amounts of filament material which becomes unusable.

To prevent these drawbacks, several devices have been proposed. One method is to offset or taper the edges of the wound spool in an inward direction to prevent the possible collapse of the edge structure. Another approach is to reduce and vary the translatory speed of the entire thread guide with respect to'the spool in the vicinity of the spool ends. A method of accomplishing this is by moving the spool a small amount in the longitudinal direction during the winding-on process as the thread approaches the end portion.

Devices such as these are expensive and unreliable due to the rather complicated kinetics and linkage mechanisms involved in moving the guide units or the displacement of the entire spool. Devices such as these tend to wear heavily, thus impairing the desired effect. In addition, they require constant supervision by skilled personnel, thus increasing the expense of the operation.

PURPOSE OF THE INVENTION An object of this invention is to impart a constant translatory motion to thread being wound upon a spool or bobbin. This is especially desirable in the end portions of the wound area.

Another object of this invention is to produce threaded spools from which the thread can be easily and freely unwound without fluctuations in the thread tension. In order to accomplish this, the avoidance of hard or built-up edges on the spools as the thread is wound is necessary.

A further object is to provide a thread guide device which prevents the built-up end areas but yet which is both structurally rugged to handle heavy threads or yarns and yet extremely simple, reliable and inexpensive.

SUMMARY OF THE INVENTION The thread guide of this invention comprises an elongated pin or shank portion which is guided in a slotted member held parallel to a left-hand thread roller. A thread roller includes an endless spiral wound guide groove which cooperates with a runner element mounted at the bottom of the thread guide. The thread roller slot imparts a translatory movement to the thread guide which is equal to the winding area of the thread spool or bobbin.

The spiral groove at each end of the thread roller contains a turnaround region where the translatory direction of the thread guide is reversed and which in turn forms the end structure of the wound spool. An elongated arm on the upper portion of the pin or shank of the thread guide can be aligned with the longitudinal axis of the runner. At the outer end of the extension arm is located a guide device to direct the passage of the winding thread.

The thread is accelerated in the reverse direction ahead of the thread guide movement by means of the angular displacement of the extension arm. The outer end of the extension arm which guides the thread reverses and angularly moves back across the spool as the guide runner passes through the turnaround portion of the guide groove. This angular acceleration at the tip of the extension arm and the thread being guided through it reduces the delay time in winding the end portion of the spool, thus preventing the built-up area. The length of the extension arm determines the rate of acceleration of the thread during the movement of the thread guide runner through the roller turnaround area. Thus, depending upon the constant ratio of rotation between the thread roller and the wound spool, the desired acceleration to prevent the built-up area can be determined.

The extension arm which is aligned with the runner or contact unit of the thread guide follows an acute angle with respect to the thread roller while moving in one direction. This angle varies in the region of the turnaround by moving from the acute angle to a position which is transverse to the longitudinal axis of the roller and then to an opposite acute angle as the extension arm moves in the reverse direction. The acute angles are equal but opposite to each other with respect to the longitudinal axis of the roller.

' In this method, the angular movement of the thread guide at the end of the extension arm compensates for the reduction in movement of the overall thread guide in the region of the turning curve of the roller resulting in equalized compensation for the reduction in translatory movements of the contact unit in this region. This results in a continuous translatory speed or movement of the thread being wound in the end regions.

In this fashion, the thread guide device is extremely simple and light in weight. With a device such as this, a decrease in the moving or driving force is obtained, resulting in the ability to move the thread guide across the transverse spool or bobbin at a substantially increased rate of speed. A translatory speed of 2,000 to 3,000 alternate strokes per minute is possible with this device.

Various types of structures for the thread guide including single or double guide groove runners are provided in this disclosure. In addition, in order to properly wind spiral spools, it is possible to reposition the longitudinal guide way for the thread guide device with respect to the thread roller and to vary the positions of the extension arm with respect to the runners to compensate and obtain the desired end structure for conically wound spools.

BRIEF DESCRIPTION OF DRAWINGS Other features of this invention will appear in the following description and appended claims, reference being made to the accompanying drawings forming a part of the specification wherein like reference characters designate corresponding parts in the several views.

FIG. 1 is a side elevational view of a thread guide according to the present invention;

FIG. 2 is a front view of the thread guide shown in FIG. 1;

FIG. 3 is a top plan view of the thread guide shown in FIG. 1;

FIG. 4 shows a side elevational view in diagrammatic form of the thread guide of this invention in combination with a left-hand thread roller and spool;

FIG. 5 is a top plan view of the thread guide and lefthand thread roller of FIG. 4;

FIG. 6 is a side elevational view of another embodiment of a thread guide made in accordance with this invention;

FIG. 7 is a front view of the thread guide shown in FIG. 6;

FIG. 8 is a top plan view of the thread guide shown in FIG. 6;

FIGS. 9a and 9b are top plan views in diagrammatic form showing the thread guide of FIG. 6 in various moving positions with respect to the left-hand thread roller;

FIG. 10 is a front view of another thread guide embodiment showing a guide rail slider and position stabilizer;

FIG. 11 is a side elevational view of the thread guide of FIG. 10;

FIG. 12 is a top plan view in diagrammatic form showing the thread guide of FIG. 10 in combination with a left-hand thread roller;

- FIG. 13 is a sectional view in diagrammatic form of another thread guide embodiment showing its relation with a left-hand thread roller;

FIG. 14 is a plan view in diagrammatic form taken along line XIV-XIV of FIG. 13;

FIGS. 15, 16 and 17 are top views in diagrammatic form showing the angular movement of the thread guide extension arm of FIG. 13 as it moves through the turnaround section of a left-hand thread roller;

FIG. 18 is a sectional view'in diagrammatic form of another embodiment of the thread guide having adjustable extension arm positioning and its relation with the left-hand thread roller;

FIG. 19 is a top plan view of the extension arm of FIG. 18; and

FIG. 20 is a diagrammatic presentation showing the relationship of a conical thread spool and the parallel angular adjustment of the thread guide with respect to the longitudinal axis of the left-hand thread roller.

DESCRIPTION OF SPECIFIC EMBODIMENTS It is common practice in the winding of thread spools or bobbins to guide the thread during the winding process by means of a thread guide. The thread guide is moved back and forth along the longitudinal axis of the spool by a contact or moving unit having a spiral shaped endless guide groove 3 including a turning curve 10 at each end of the path of movement. The longitudinal axis of the moving unit is generally held in parallel relation to the longitudinal axis of the thread spool. This function is usually performed by a device called a left-hand thread roller or a thread guide interacting with the guide rail of an eccentric.

As shown in FIGS. 1-5, a thread guide device 1 of this invention includes a guide slot runner la which is designed to engage the spiral guide groove 3. A pin portion 2 extends perpendicularly from the axis of the runner la. An extension arm 4 is connected to pin portion 2 in a plane perpendicular to the axis of the pin 2. The longitudinal axis of the extension arm 4 is generally aligned with the longitudinal axis of the runner la. On the outer end of the extension arm 4 is mounted a guide unit 5 which is usually arranged perpendicular to the arm 4 for guiding the thread during the spool winding operation. It is to be understood that the guide unit 5 can consist of any suitable design such as a fork, an eye, or the like.

Surrounding pin 2 is a collar 2a which provides a bearing surface on the underside of the guide rails 8. The collar 2a and the extension arm 4 provide a securing arrangement for preventing the contact or thread guide unit 1 from being lifted out or displaced from the guide member 8. The longitudinal slot 7 in the guide member 8 is generally arranged parallel to the axis of the transverse thread spool 9.

The thread guide device 1 is slidably mounted in the slot 7 with the runner la fitted in the endless guide groove 3. The device 1 is moved in a translatory fashion across the length of the transverse spool 9 by the rotation of the roller 6. The thread roll 6 and spool 9 can be driven simultaneously by any type of drive device (not shown). It is desirable to maintain a predetermined ratio of the turning speed of the spool 9 with respect to the turning speed of the thread roller 6. In this fashion, the translatory speed of the thread guide 1 moving back and forth across the length of the thread spool 9 is controlled. The thickness of the thread to be wound on the spool 9 is the primary consideration in determining the turning speed ratio so that an even and smooth wrap can be obtained.

As the thread guide device 1 passes into the region of the turning zone of the endless spiral groove 3, the angular position of the thread guide constantly changes. This change includes a movement from an acute angle of the extension arm 4 in the direction of movement passing through a position which is perpendicular to the longitudinal axis of the spool 9 and then into an acute angle in the opposite direction as the direction of the thread guide device 1 reverses. The extension arm 4 thus swings through an angular range 11 as shown in FIG. 5 during the turnaround movement.

The thread leading through the guide unit 5 receives an angular acceleration as the runner la passes through the turning zone 10 in the thread roller groove 3. While the thread guide device 1, in its translatory movement,

decelerates to zero and then accelerates in the opposite direction at the end of the thread spool 9, the extension arm 4 undergoes an angular acceleration along with the guide unit 5. This angular acceleration imparts an added acceleration to the thread in the return winding direction. The added acceleration or speed increase of the thread compensates for the reduced translatory speed movements of the thread guide device 1. In other words, the translatory movement of the thread at guide unit 5 is increased in the region of the turning curve 10. Therefore, by the'superimposition of the components of the angular acceleration for the unit 1 in the direction of slot 7 and for the extension arm 4, the normal translatory speed of the thread can be obtained. By varying the length of the extension arm 4, the magnitude of the compensation can be altered to a greater or lesser degree as desired. Because of the speed compensations discussed hereinabove, the build-up of thread at the ends of the transverse spool is prevented.

In the embodiment shown in FIGS. 6-9b, the thread guide device 12 includes a structure which is similar to the embodiment of FIG. 1 except that a-diamond or rhombic shaped collar or sliding block 13 is provided on the pin 2. The long axis of the diamond-shaped collar 13 extends transversely to the extension arm 4 and runner 1a, while the narrow dimension is aligned parallel with these two elements. The guide way member 8 as shown in FIGS. 9a and 9b includes an undercutsection (not numbered) along the, inner edges of the slot 7. The short dimension of the diamond-shaped collar 13 has a size effective to fit the width of the undercut portion across the slot 7. As is evident from the drawings, the thickness of the collar 13 is less than the width of the inner edges of the guide slot 7 as measured in a direction parallel to the axis of the pin 2. As the thread device 12 moves to the left across the thread roller 6 as shown in FIG. 9a, the elongated sides 13a of the collar 13 ride in the respective undercut portions of the slot 7. In moving in the reverse direction as shown in FIG. 9b, the thread guide device 12 with its extension arm 4 rotates so that the elongated edges 13b of the collar are now in contact with the undercut portions of the slot 7. The undercut portion prevents the thread guide device 12 from being lifted out of the slot 7 while at the same time provides a guiding surface for limiting the angular rotation of the thread guide member 12 with respect to the roller 6. The angles of the diamondshaped collar 13 will depend on the angular inclination of the spiral guide groove 3 on the left-hand thread roller 6. As shown, the extension pin 2 is out of or not in contact with the guideway member 8.

In the embodiment of FIGS. 6-91), the thread is guided by guide unit 5 of the guide device 12. The thread travels at uniform speed corresponding to the inclination of the spiral groove 3 and the rpm. of the thread roller 6 as far as the region of the turning zone 10. At this point, the guide unit 5 experiences a deceleration of translatory speed that is proportional to the reduced inclination of spiral guide groove 3.

In the FIGS. 1042, thread guide device 14 has a rectangular slide block collar 15. Block 15 is pivotally supported around the pin 2a and thereby permits the thread guide device 14 to rotate with respect to the block 15. Guide bushing 16 reinforces the hole in the rectangular slide block 15. The pin 2a has a head portion 2b upon which supports a pin elongation extension for rotational movement around the transverse axis 17. The extension arm 4a and guide unit 5a is attached to the upper end of the elongated pin portion 2c.

An arm 18 extends from the side of the elongated second pin portion 20 with lug l9 flexibly engaged thereto. The lug 19 can be brought into connection with a known end-laying device by means of an appropriate transmission rod (not shown). Consequently, the thread guide device 14 moves in the same pivotal movement by means of runner lb as disclosed in the previous embodiments. In this embodiment, however, the extension arm 4a and guide unit 5a have the capacity to pivot transversely with respect to the runner lb. That is, the second pin portion 20 is pivotally mounted on the extension pin 2a so that its angular relationship with respect to the collar 15 may be varied. This permits the varying of the length of the translatory movements of the guide device in the region of the ends of the thread spool. This embodiment permits the formation of a thread spool of biconical structure. Additionally, the angular movement of extension arm 4a around the longitudinal axis of the pin portions 20 and 2c prevents buildup of threads at the ends of the spool. Fur thermore, such buildup is prevented because the transverse spool is provided with so-called sliding ends.

As shown in FIG. 12, the guide groove 3 of the lefthand thread roller 6 includes a central ridge (not numbered) which fits into the U-shaped runner lb. The rectangular slide collar 15 is guided along the guide slot 7 by members 8.

In the embodiment as shown in FIGS. 13-20, the lefthand thread roller 21 is rotatably mounted within a casing 22 which is covered by a lid 23. Two guide slot contact runners 25 and 26 engage, in succession, the spiral guide groove 24. Each runner unit 25 or 26 is pivotally mounted in the slide members 29 and by means of the pins 27 and 28. Slide members 29 and 30 are guided parallel to the axis 21a of the thread roller 21 by the elongated guide rod 31. In this embodiment, the slide members 29 and 30 include forked portions 34 and 35 respectively. Theforked portions 34 and 35 include aligned mounting holes and are arranged in staggered relation on the guide rod 31 by the offset design of the brackets 29 and 30. The outer edges 36 and 37 of the slide members 29 and 30 are guided by the respective slots 38 and 39 provided in the roller support casing 22. These grooves 38 and 39 extend the entire length of the thread roller 21.

The slide members 29 and 30 support mounts 40 and 41 which include respectively pins 42 and 43. An elongated extension arm 44 includes holes which correspond to the location of the pins 42 and 43. At the free end of the extension arm 44 which extends through a slot 32 in the casing 22 is located an upwardly extending thread guide unit 45.

In FIGS. -17 a diagrammatic presentation shows how the extension arm 44 is controlled by the successive contact units and 26. In the position of the parts shown in FIG. 15, both contact units 25 and 26 are aligned with the straight portion of the spiral guide groove 24. As the contact unit 26 passes into the turning region of the guide groove 24, contact unit 26 executes an angular translatory movement relative to contact unit 25 in a direction towards the opposite end of the thread roller. The extension arm 44 executes a pivotal movement around the contact unit 25 and passes through the transverse position of FIG. 16 to the position shown in FIG. 17. As both contact units 25 and 26 again align with the straight guide groove portion 24, the extension arm 44 again follows the alignment of the slot 24. At the other end of the thread roller 21 the extension arm 44 goes through the same pivotal movement but in the opposite direction.

In FIGS. 18 and 19, the extension arm 50 consists of base 44a and elongated portion 50a. The elongated portion 50a has guide unit 45 mounted on one end. The portion 50a is fixedly pivotally adjustable relative to the base 44a and longitudinal axis 21a of the roller 21 by means of the slots 46, 47 and fastening members 51, 52. Any type of fastening members such as wing nuts and threaded studs or the like can be used in this embodiment. The slots 46, 47 are designed in an arcuate fashion to permit the pivotal adjustment. The straight guide rod 31, along which the slides 29 and 30 move, can also be set at an oblique angle to the roller axis 21a. For this purpose, the slide rod 31 can be adjusted by having its ends supported in suitable fixtures (not shown) which can be adjustably positioned.

The adjustable positioning of the slide rod 31 is used when the thread is to be wound on a conical spike or spool 49. The oblique positioning of the rod 31 depends on the contour line 49a of the conical spike 49. The guide rod 31 is positioned parallel to the surface 490.

In this configuration, it is desirable that the ends of the threaded portion wound on the spiral spike 49 do not stand perpendicular to the winding surface 49a. If the ends were perpendicular to the surface 49a, a thread overhang portion would occur at 48b. To prevent this, the elongated portion 50a of the extension arm 50 is pivoted relative to member 44a in a direction opposite and the same angular amount as the oblique angular positioning of the slide guide 31. In this way the threaded portion 48 can be formed whose contour line 48a runs parallel to the contour line 49a while the end surfaces 48b and 480 remain perpendicular to the longitudinal axis of the conical spike 49.

With the spaced contact units 25 and 26 as shown in the embodiments of FIGS. 13 and 18, the contact arms or runners and grooves can be formed with a shallower depth so that the friction at the turning points will be less. At the same time the angular pivoting of the extension arm 44 or 50 is substantially more reliable. The structure of these embodiments permits a more robust construction and allows the guide device to be used with heavier threads or yarns, including carpet yarns.

While a thread guide device has been shown and described in detail, it is obvious that this invention is not to be considered as being limited to the exact form disclosed, and that changes in detail and construction may be made therein within the scope of the invention, without departing from the spirit thereof.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

l. A thread guide device having a thread guide for winding thread onto a rotating transverse thread spool, said device comprising:

a. a rotatably mounted thread roller having an endless spirally wound groove extending longitudinally along the surface thereof and disposed in parallel relationship with said thread spool,

b. guide means longitudinally disposed with respect to the thread roller and extending along the length of the thread roller,

0. two runner means successively slidably disposed within the spiral groove for running along said spiral groove,

d. first and second slide means movably mounted on said guide means for parallel movement with respect to the axis of the thread roller and along the length thereof,

e. each said first and second slide means rotatably carries one of said runner means, and

f. an extension arm means is mounted to pivot on each said first and second means and carries said thread guide.

2. A thread guide device as defined in claim 1 wherein said first and second slide means comprises first and second slide members rotatably mounted on said guide means for parallel movement with respect to the axis of the thread roller,

each said runner means is rotatably mounted in a respective slide member and said extension arm means is mounted to pivot on each said slide member.

3. A thread guide device as defined in claim 2 wherein said guide means includes an elongated rod extending longitudinally with respect to the thread roller and said slide members include forked prong sections which slidably engage said elongated rod.

4. A thread guide device as defined in claim 3 wherein said prong sections are arranged on said rod whereby said slide members are offset with respect to each other.

5. A thread guide device as defined in claim 1 wherein said guide means is positionally adjustable at a predetermined angle with respect to the longitudinal axis of the thread roller so that the thread may be wound onto a conically shaped thread spool.

6. A thread guide device having a thread guide for winding thread onto a rotating transverse thread spool, said device comprising:

a. a rotatably mounted threaded roller having an endless spirally wound groove extending longitudinally along the surface thereof,

b. guide means longitudinally disposed with respect to the thread roller,

0. two runner means successively slidably disposed within the spiral groove for running along said spiral groove,

9 10 d. slide means movably mounted on said guide means g. said extension arm means includes a base portion for parallel movement with respect to the axis of hi h i t on aid slide means and a projecting the thread roller, element e. each said runner means is rotatably mounted in said slide means, and

f. an extension arm means is mounted to pivot on said slide means and carries said thread guide,

h. said projecting element being fixedly pivotally adjustable with respect to said base portion. 

1. A thread guide device having a thread guide for winding thread onto a rotating transverse thread spool, said device comprising: a. a rotatably mounted thread roller having an endless spirally wound groove extending longitudinally along the surface thereof and disposed in parallel relationship with said thread spool, b. guide means longitudinally disposed with respect to the thread roller and extending along the length of the thread roller, c. two runner means successively slidably disposed within the spiral groove for running along said spiral groove, d. first and second slide means movably mounted on said guide means for parallel movement with respect to the axis of the thread roller and along the length thereof, e. each said first and second slide means rotatably carries one of said runner means, and f. an extension arm means is mounted to pivot on each said first and second means and carries said thread guide.
 2. A thread guide device as defined in claim 1 wherein said first and second slide means comprises first and second slide members rotatably mounted on said guide means for parallel movement with respect to the axis of the thread roller, each said runner means is rotatably mounted in a respective slide member and said extension arm means is mounted to pivot on each said slide member.
 3. A thread guide device as defined in claim 2 wherein said guide means includes an elongated rod extending longitudinally with respect to the thread roller and said slide members include forked prong sections which slidably engage said elongated rod.
 4. A thread guide device as defined in claim 3 wherein said prong sections are arranged on said rod whereby said slide members are offset with respect to each other.
 5. A thread guide device as defined in claim 1 wherein said guide means is positionally adjustable at a predetermined angle with respect to the longitudinal axis of the thread roller so that the thread may be wound onto a conically shaped thread spool.
 6. A thread guide device having a thread guide for winding thread onto a rotating transverse thread spool, said device comprising: a. a rotatably mounted threaded roller having an endless spirally wound groove extending longitudinally along the surface thereof, b. guide means longitudinally disposed with respect to the thread roller, c. two runner means successively slidably disposed within the spiral groove for running along said spiral groove, d. slide means movably mounted on said guide means for parallel movement with respect tO the axis of the thread roller, e. each said runner means is rotatably mounted in said slide means, and f. an extension arm means is mounted to pivot on said slide means and carries said thread guide, g. said extension arm means includes a base portion which pivots on said slide means and a projecting element, h. said projecting element being fixedly pivotally adjustable with respect to said base portion. 